1. Field of the Invention
The present invention relates to the repair of texturized walls and ceilings in residences, office buildings and the like. More specifically, the present invention relates to methods and apparatus for a portable, handheld pressurized hopper gun for use in patching acoustic ceilings and repairing cracks and damage in and the texturizing of walls and ceilings by applying a texturized sealing compound thereto.
2. Description of the Related Art
The relevant art is directed to hopper type spray devices used in the building trades. The hopper type spray devices of the prior art are typically employed for use in (a) texturizing of walls and ceilings and (b) plaster patching. Several hopper type spray devices are known in the prior art.
One example comprised a drywall hopper apparatus having a hopper container in which drywall repair ingredients were mixed by hand and poured into the hopper container. In the alternative, the hopper container could be motorized to provide rotational motion for mixing the ingredients. Once mixed, a pump was employed to draw the mixed ingredients through a material hose. The material hose was positioned parallel to a separate air hose and the two hoses intersected at the input of a hand gun or hand pole having a spray head. The separate air hose supplied pressurized air to the spray head to aerate the mixed ingredients for spraying onto a ceiling. Optionally, a switch could be located on the drywall hopper apparatus for use in controlling the operation of the pump.
This prior art drywall hopper apparatus clearly exhibited antiquated means for patching of plaster and texturizing of walls and ceilings. The apparatus was large and difficult to handle and thus was not conveniently portable. The necessity of separate material and air lines made the apparatus even more inconvenient and difficult to transport into residences and offices. The motorized hopper container or mixer typically remained out of doors while the material and air lines were pulled into the room of the residence or office to be repaired. Often the walls, floors and carpets of the residence or office were soiled or even damaged by the equipment.
Another example of the prior art included a portable drywall hopper gun (known by the tradename Marshalltown) utilized for smaller repairs of texturized walls and ceilings. The portable drywall hopper gun included a funnel-shaped, handheld hopper which received the mixed ingredients. The funnel-shaped hopper was vertically attached to a hand gun device having a handle and trigger mechanism. Low pressure air was fed into the rear end of the hand gun device. The mixed ingredients were gravity fed down through the funnel-shaped hopper. Actuation of the trigger released the air which forced the mixed ingredients out of an adjustable orifice plate onto a wall or ceiling to be repaired. Once sprayed, the texture of the mixed ingredients could be finished with a trowel.
Several problems existed in the handheld portable drywall hopper gun known in the art. One problem was that the flow of the mixed ingredients down into the funnel-shaped hopper could not be controlled. In particular, the mixed ingredients that were intended to be gravity fed into the hand gun device often would not flow at all. In order to address this problem, liquid soap was mixed with the ingredients to form a solution which promoted the flow thereof. Unfortunately, when the trigger mechanism was actuated to admit air into the hand gun device, the mixed ingredients often failed to spray out the orifice and onto the wall or ceiling to be repaired. If the mixed ingredients were further liquified, then the texture of the resultant mixed ingredients was too fluid and would not match the texture of the wall surface surrounding the damaged portion to be repaired. Specifically, the texture of certain sealing compounds utilized on the ceiling surface (often referred to as "popcorn"), would not be sufficiently dense.
Another problem experienced with the portable drywall hopper gun included the clogging of the port leading from the bottom of the funnel-shaped hopper into the hand gun device. The mixed ingredients poured into the funnel-shaped hopper comprise a drying material, not a setting material. Even when mixed properly, the mixed ingredients would begin to dry and thus refuse to gravity flow down the port leading from the bottom of the funnel-shaped hopper into the air channel of the hand gun device. Further, the operation of the portable drywall hopper gun of the prior art was inconsistent and intermittent. The drywall hopper gun would operate and then not operate while periodically being totally inoperative. Even when the proper mixed ingredients (i.e., having a smooth grainy consistency) designed for this drywall hopper gun was employed, the drywall hopper gun would still not operate consistently.
An additional problem existing with the drywall hopper gun of the prior art is that the funnel-shaped hopper is open at the top. This presents the problem of loosing the mixed ingredient load to spillage. Further, the mixed ingredients of the funnel-shaped hopper is at atmospheric pressure which fails to overcome the problems associated with the mixed ingredients drying and clogging as discussed hereinabove. Other untranslated references that appear to be related to the present invention include German Document 917 895 (1954), German Document 1 065 337 (1955) and Belgium Document 504 615 (1951).
Thus, there is a need in the art for a handheld pressurized hopper gun that is conveniently portable, includes a low pressure air input at the base of the handle of a spray gun that continuously feeds low pressure air to both the spray gun and a pressurized sealed hopper through air regulating devices to provide flow control of the mixed ingredients and to prevent damage to the sealed hopper, where the spray gun includes a trigger that when actuated causes only the mixed ingredients to be dispensed and a hollow plunger shaft that continuously passes pressurized air from the air input through the spray gun to force mixed ingredients out a nozzle orifice.